Telephone system



J. L. McQUARRlE.

TELEPHONE SYSTEM.

APPLICATION FILED 050.30. 19x6.

Patented Apr. 20, 1920.

2 SHEETSSHEET l- In venror:

James 1'7 Qua rrl'e y .l. L. McQUARRIE. TELEPHONE SYSTEM. APPLICATION FILED DEC. 30, 1916.

Patented Apr. 20, 1920.

2 SHEETS-SHEET 2.

/n v en for: James L. lV- yuarrie.

fi as na line finder.

UNITED STATES PATENT OFFICE.

JAMES L. MCQUARRIE, OF MONTCLAIR, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, 035 NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented Apr. 20, 1920.

Application filed December 30, 1916. Serial No. 139,835.

To all whom it may concern:

e it known that I, JAMES L. a citizen of the United States, residing at Montclair, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to an automatic telephone system in which calling lines and called lines are automatically connected for conversational purposes by a minimum of apparatus, a large portion of the apparatus utilized in establishing the connection being released and made available for use in establishing other connections, while only a sn1all portion of such apparatus is retained in use in association with a completed connection.

In accordance with a feature of the invention, when a call is initiated, a line finder switch is employed to hunt for and seize the calling line, and this hunting operation of the line finder is utilized for the purpose of associating a connecting or trunk circuit with the calling line independently of the line finder. In accordance with this feature of the invention either the setting move- Inent of the line finder or the restoring movement of such line finder may be utilized to direct a separate connector switch, associated with the trunk or connecting circuit, to the multiple terminals of the calling line.

In accordance with a related feature of the invention there is associated with each line finder a registering and controlling equipment comprising registers which are. adapted to be set to register the designation of a calling line under the control of either the setting or restoring movement of the a. connector switch for the purpose of directing such connector switch to multiple terminals of the calling line.

In accordance with afurther feature of the invention a plurality of trunk lines are provided, any one of which may be utilized for the purpose of connecting a calling and a called line, the connection with the calling line being controlled by the operation of a separate line finder, Which hunts for and seizes the calling line when tiated. and the connection of utilized to control the trunk to by a sending device, which maybe either located at the MoQUAiniIE,

These registers are afterwardv a. call is ini-- subscribers substation or which may be operated by an operator at an exchange. In accordance with a related feature of the invention a selector switch is provided, associated with each line finder, which is operated after the line finder has seized the calling line to automatically select an idle trunk line and to place connector switches, associated with such trunk line, into operative relation with the line finder, for controlling the connection of the trunks to the calling line, and with the sending device for the purpose of associating the trunk with the called line.

11 accordance with still another feature of the invention, there may be associated with the line finder and trunk selector a registering and controlling equipment for registering both the designation of the calling and the called line, which equipment may be subsequently utilized to control the connection of the trunk with both the calling and called lines.

Other and. related features of the invention. not specifically referred to above, will appear more clearly from the detailed description and the accompanying drawings showing the preferred embodiment of the invention. in which Figure 1 represents a line finder. a registering controlling equip ment and a trunk selector common to a group of lines; and Fig. 2 represents a trunk line and associated calling and called line connectors.

The particular en'ibodiment of the invention described herein is shown as applied to a ten-thousand line system in which the lines are grouped both as calling and called lines into groups of one thousand. There is provided for each group of one thousand lines. considered as calling lines, a plurality of line finders, such as LF. each of which has access to each of the thousand lines. These line finders are very similar in mechanical construction to the switches shown in Patent 1204.466 to J. L. McQuarrie. There are ten common trip magnets, such as shown at and ten sets of brushes for each switch. each set of brushes having access to a group of one hundred lines.' The switch is arranged to be driven downward from its topmost ornormal position to find the line. The reason for this (OIlStlllCtl0n1Wlll appear in the description of the line finding operation. Each line finder LF is associated, with although the units register a trunk selector LS in a registering and control circuit. The trunk selectors are of the type shown in Patent. No, hit 33,696 to Craft and Reynolds, and are adapted to select idle trunks such as shown in Fig. 2. The trunk selectors are provided With ten sets'of brushes, each set of brushes having access to trunks leading from the one thousands group to which the line finder and trunk selector are individual to one of the other one thousands groups of lines, considered called lines, of which there are ten. Tl'ierefore, in a ten-thousand line exchange there will be ten sets oi trunks, such as shown in Fig. 2, leading from each group of calling linesto each group of called lines, so that any calling line may be connected to any called line in its own or any other group. The sequence switches of the type disclosed in Patent 1,127,808, issued February 9, 1915, to d. N. Reynolds and C. F. Baldwin and in tracing circuits the contacts of the sequence switches will be referred to contacts followed by the position number in parentheses. The general operation of the system is follows: When a call is initiated a-relay individual to the sub-group in which the calling line is located, is energized and operates the line finder trip magnet individual to the subgroup, tripping the set of brushes having access to the sub-group of one hundred lines. This group relay also serves to set the calling line hundreds register to register the complement of the hundreds digit of the calling line. As all of the registers employed are of the unidirectional type, that is to say, they are stepped from normal position to a set position, and from the set position back to normal without reversing their direction of movement. They are set in a position corresponding to the complement of the number of controlling impulses desired, and move forward tonorinal position in their impulse controlling move rent. The energization of the group relay also brings about the downward movement of the line finder to hunt for the calling him. The line findeiwis provided with two commutators, one of which includes ten seg ments, over one ofwhich the :orresponding commutator brush as the line finder brushes pass over a group of ten lines, and the other including a segmentfor each line.

is the line finder moves down to the terminal of the calling line, the two brushes pass ing, over the conunutators send impulses which serve to set the calling line tens and units registers respeci'aivel' =,n As the line finder moves downward and as the lines are arranged with the lower 1" ihered e at the bottom, these registers in positions correspondine' to the lenient the tens and units oi its of ling line,

ma sevinserts eral complete revolutions before the called line is reached, as the units register will obviously make onerevolution for each step of the tens register. As soon as the line finder has seized the calling line, the calling subscriber operates his substation sender, which may be the usual finger Wheel araiiged to send impulses equal in number to the complement of the digit dialed. T he first s t of impulses sent sets the called line thousands register, the second set the called line hundreds register, the third, the called line tens register, and the fourth, the called line units register. As soon as the called line thousands register is setthe thousands group of the called line is determined and the register operates to select the brush of the trunk selector having access to trunks, such as shown in Fig. 2, extending to that group. As soon as the brush is selected the trunk selector is started to hunt for an idle trunk in such group. When such trunk is found the calling line connector of such trunk operated under the control of the calling line registers to connect the trunk to the calling line, and then the called line connector is operated under the control of the called line registers,.thus directly connecting the calling and the called line. When the connection is thus established the line finder and trunk selector are restored and may be used in connection with other calls.

Although, in the preferred embodiment of the invention as disclosed, registers are used for controlling the connectors, such registers may be omitted without departing from the spirit of the invention. If no registers are employed the calling line connector may be operated under the control of the substation sender and the calling line. connector may be controlled by an interrupter op erated by the line finder when such line finder is restored to normal.

As the general plan and operation of the system has been described the detailed operation in establishing a complete connection will non/ be described. It will be assumed for the purpose of illustration that a call is initiated on line two-five-six-two for line five-seven-eight-one. Therefore, the line finder LF, trunk selector LS and calling line connector LC are individual to from battery, through relay 2, contact and inner armature of the line relay 1 to ground. The relay 2 is a group relay common to th 1 sub-group of one hundred lines in which the calling line is located, being operated when any line relay in the sub-group operates.- The relay 2, at its outer right-hand armature, establishes a circuit for the trip magnet 5, individual to the sub-group in which the calling line is located, which circuit extends from battery, trip magnet 5, contact and outer armature of the group relay 2, to ground. A circuit is also established at the outer armature of the relay 2 for the relay 3, which circuit extends from battery, contact 101 (position 1), relay 3, contact and outer armature of: the relay 2, to ground.

The relay 3 when energized establishes a circuit for relay 4, which circuit may be traced from battery, relay 4,'contact 102 (position 1), conductor 29, conductor 30, contact 103 (position 1), contact and left armature of relay 3 to ground. The relay 4 at its right-hand armature establishes a circuit to drive the sequence switch 100 into position 2, which circuit extends from battery, through the motor magnet of the sequence switch 100, contact 104 (position 1), front contact and right-hand armature oi. relay 4 to ground. W'ith the sequence switch 100 in position 2, the previously traced energizing circuit from relay 4 .is interrupted. causing it to release. A circuit is also established in position 2 oi. the sequence switch 100 for the step 'iing magnet 31 of the calling line hundreds register, which circuit extends from battery. armature and back contact of relay (3. contact and armature ol magnet 31, contact 105 (position 2), magnet 31 to ground. The stepping magnet 31 interrupts its own circuit, and steps the brush 32 over the stationary terminals of the minal 33, individual to in which the calling line is located, is reached. It will be observed that when the group relay 2 was energized, ground was connected to the terminal 33 at its inner armature and contact. As it is assumed that the calling line. is located in the fifth hundreds group, the brush 32 ot the register will he stopped in position 5, since, when the brush 32 makes contact with the ter minal 33 a circuit is established for the relay (3, which circuit extends from battery, through the relay 6,,contact 106 (position 2). brush 32, terminals 33, contact and inner armature of the relay 2 to ground. Vhile the hundreds callingline register is being set, the line finder may also be operated for the purpose of finding the calling line. Thus, in position 2 of the sequence switch 100, a circuit is established for the downdrive magnet 7 of .the line'finder,

the hundreds group,

register until ter-\ .which circuit extends from battery, downdrive magnet 7, contact 107 (position 2), theback contact and armature of the relay 8 to ground. The energization of the magnet 7 causes the brush carrying shaft, indicated at 34, to be driven downward, carrying brushes 35, 30 and 37 over sets of line contacts, such as 27, 38 and 39. At the same time the interrupter brushes, indicated at 40 and 41, are moved over the commutator segments 42 and 43. It will be observed that as the brush 41 moves over the commutator 43, impulses calling line register may be traced from brush 41, commutator tact 108 (position 2), stepping magnet 25 to ground. Therefore, for each group of ten lines that the brushes 35, 36 and 37 are moved over in the downward movement of the line finder, the register brush 45 is stepped forward one step. As the calling line is number 2562, it is located in the fifth tens group from the bottom, so that after the switch has passed over five groups of tens the register brush 45 will have been moved to the fifth terminal indicated at 46. At the same time a circuit is established for the stepping magnet of the calling line units register, which circuit extends from battery, through the brush 40, commutator 42, contact 109 (position 2), magnet 26 to ground. The magnet 26 will be energized once for each line terminal that the switch passes over in its downward movement,'and as it has been assumed that the number of are sent to the tens over a circuit which battery, through the 43, conductor 44, conthe calling line is 2562, it is obvious that the magnet 26 will be energized forty-eight times, as the brush 40 will pass over fortyeight commutator segments. Therefore, the brush 47 of the units register will make four complete revolutions, and will finally be stopped on the No. 8 terminal, indicated at 48. When the test terminal 27 of the calling line is reached by the line finder test brush 35, a circuit is established for the test relay 8, which circuit extends from battery, through the outer armature of the line relay 1. test terminal 27, test brush 35, contact 110 (position 2), test relay 8 to ground, causing the energization of the relay 8. The test relay 8 is so adjusted that it will not operate in series with the cut-oll' relays ol non-calling lines. llowever, 'when the test relay operates it will he heldup in series with the cut-off relay 89, battery being supplied through the cut otl relay instead of through the armature ot' the line relay, which. releases as soon as the cut-off relay is energized. The opens the previously traced circuit for the down-drive magnet 7 so that the line finder is stopped with the brushes 36 and 37 in contact with the line terminals 38 and 39 of the calling line, and, also, as previously exrelay 8 when energized plained the register hr'ish 45 is stopped on the fifth terminal 46, and the register brush 47011 the eighth terminal 48.

With the test relay 8 energized, and with the relay 6 energized, which condition can only occur after the line has been found and the calling lino registers set, a circuit is established to drive the sequence switch 100 into position 3, which circuit extends from battery, motor magnet of the sequence switch 100, contact 104- (position 2), left-hand armature and contact of the relay 8, right-hand. armature and contact of relay 6 to ground.

In position 3 of the sequence switch a circuit is established for the relays 9 and lb, of which the relay 9 is quick-acting and the relay 10 is slow-acting. This circuit extends from battery, relay 9, contact 111 (positions 3 to 9), brush 37, terminal 39, out and over the subscribers line, including the telephone set, back to the terminal 38, brush 36, contact 112 (positions 3 to 9), relay 10 to ground. As soon as the relay 10 is energized over this circuit, a circuit is established to drive the sequence switch 100 into position 4,.from battery, motor magnet of sequence switch 100, contact 113 (position 3), conductor 49, front armature and contact of relay 10 to ground. )Vhen the sequence switch 100 reaches position 4 the apparatus is in condition to receive the controlling impulses from the substation sender. It will be observed that the circuits over which the called line registers are set include sequence switch contacts which are closed in position 4 to 9. As soon as the first or thousands set of controlling impulses has been registered in the called line thousands register, this register may be used to control the trunk selector to pick out an idle trunk extending to desired thousands without waiting for the setting of the called line hundreds, tens and units registers. The setting of the remaining called line registers may take place simultaneously with the operation of the trunk selector. For the sake of simplicity, howerer, the setting of these registers will be first described.

l Vith the sequence switch in position 4 when the substation sender is operated. the relay -9 is energized and deinergized for each impulse from such sender and the relay 10 remains energized until the impulse circuit is opened for a long interval at the end of each series of impulses. As it has been assumed that the number of the called line is 5781, there will be live thousaiuls impulse... and, consequently, the relay 9 is energized and deenergized five times, and closes the circuit for stepping n'lagnet 11 of the thousands register five times, which circuit extends Irom cattery, armature and contact oi the reiay 9, Contact 153 (positions 4 to 9),

conductor 50, ierohand armature and k mntect the counting relay 13, contact (position 4), stepping magnet 11 to ground.

line thousands registers has been moved to fifth terminal 52 of the register, the impulse circuit is opened for a longer interval at the substantion. sender, permitting the slow relay 10 to decnergize. The deenergization of the relay 10 permits the energization of the counting relay 13 over the following circuit: battery, relay 12, relay 13, inner armature and contact of relay 12, conductor 53, contact 115 (positions 4 to 9) to ground. The release of the slow relay 10 also establishes a circuit for the relay 4, from battery relay 4, contact- 102 (position 4), conductor 29, conductor 30, contact 107 (position 4), back contact and armature of relay 10 to ground. The relay 4 when energized establishes a circuit to drive the quence switch 100 into position 5, which circuit extends from battery, motor magnet of the sequence switch 100, contact 104 (position 4), front contact and right armature of relay 4 to ground. In position 5 of the sequence switch the relay 4 islocked up over a circuit from battery, relay 4, front contact and left armature thereof, contact 115 (position 5) to ground. 7

In the meanwhile the impulse circuit is again established and the relays 9 and 10 energized as before. In response to the hundreds impulses, three in number, the relay 9 closes the following circuit three times; from battery, armature and Contact of relay 9, contact 133 (positions 4 to 9),

conductor :30, left armature and front contact of relay 13, left armature and back contact of relay 15, contact 109 (positions i-l to 9) stepping magnet 18 to ground. The stepping magnet 18 steps the brush 54 of the called line hundreds register to the third terminal 55. The energized relay 10 establishes at the same time a circuit for the counting relay 14, from battery, relay 14, right armature and back contact of counting relay 15, right armature and front con tact of relay 13, contact 113 (positions 4 to h), conductor 49, armature and front contact of relay 1() to ground. The counting why 15 is not energized by the operation \of relay 14 until: the shunt isremoved therefrom at the termination of the hundreds in pulses by the consequent release of relay-10.

{it the e (ls oi the hundreds impulses, the relays 9 .10 both being cleenergized, the

' and front contact relay 15 is energized so that, when the tens impulses are placed on impulse control circuit in response to thewenergization of the relays 9 and 10, counting relay 16 is energized over the following circuit: from battery, counting relay 16, right armature and back contact of counting relay17, right armature and front contact of counting relay 15, right armature and front contact of counting relay 13, contact 113 (positions 4 to 9), conductor 49, armature and front contact of relay 10 to ground. Therefore, when the tens impulses are re ceived, which, in the case assumed, are two, the relay 9 is deenergized twice setting the brush 56 on the second terminal 57 of the calling line tens register. The setting cir cuit for this register extends from battery, through the armature and contact of the relay 9, contact 133 (positions 4 to 9), conductor 50, front contact and left armature of the counting relay 13, front contact and left armature of the counting relay 15, left armature and back contact of the counting relay 17, contact 108 (positions 3 to 9), stepping magnet 19 to ground. At the termination of the-tens impulses the relay 10 is deenergized, permitting the counting relay 17 to energize so that when the units impulses are received, which, in the case assumed, will be nine in number, the brush 58 of the calling line units register will be set upon the ninth terminal 50 thereof over a circuit which extends from battery, through the armature and contact of relay 9, contact 133 (positions 9), conductor 50, left amature and front contact of counting relay 13, left armature of counting relay 15, left armature and front contact of counting relay 17, contact 106 (positions 3 to 9), stepping magnet 20 to ground.

It will be recalled that was operated in position 4 gized through the fifth position of the se quence switch 100 over a locking circuit which extended to contact 115 (positions 4 and5). As this relay remains energized in position5, ,the sequence switch 100 is thereby moved to position 6 over a circuit which extends from battery, through the motor magnet of tact 104' (position 5), front contact and right armature of the relay 4 to ground. As the sequence switch 100 reaches position 6, which positionit reaches as soon as the called line thousands register has been set, a circuit is established for the up-drive magnet. 21 of the trunk selector LS, which circuit extends from battery to the up-drive magnet 21, contact 116 (positionfi), right- Handarmature and front contact of the relay 4 to ground.

s soon as the when the relay 4 it was held enersequence switch 100 reaches position 4%, relay 4 is held energized over a circuit which extends from battery,

sequence switch 100, conthrough the relay 4, front contact and left armature thereof,,contact 102 (4 3; to 6), conductor 29, normal contact 60 of the called line thousands register, contact 114 (4% to 6), stepping magnet 11 to ground. In position 5% to 6 the commutator 61 of the trunk selector LS is connected between the relay 4 and the stepping relay 11 at contact 102. As due to the energization of the up-drive magnet, the brush passes over thegroup segments of the commutator 61, the stepping magnet 11 of the called line thousands register is shunted, causing the stepping magnet 11 to step. Therefore, in the case assumed, after five shuntings of the stepping magnet 11, the circuit of relay 4 and magnet 11 is opened by the normal register contact 60. The deenergization of the relay 4 causes the denergization of the up-drive magnet 21, and the brush carrying shaft of the trunk selector LS is stopped in a position to trip the fifth set of brushes, as such fifth set of brushes has access to trunks leading sand. sequence switch 100 is driven out of position 6 by a circuit which extends from battery, through the power magnet of the sequence switch 100, contact 104 (position 6), back contact and right-hand armature of the relay 4 to ground. 1V hen the sequence switch 100 reaches position 7 an energizing circuit is established for the test relay 22, which circuit extends from battery, through the left-hand winding of such relay 22 to the contact 117 (positions 7 to 8), to ground. As soon as the relay 22 is energized a -i1' cuit is established to drive the sequence switch 100 into position 8, which circuit extends from battery, through the motor magnet of sequence switch 100, contact 118 (position 7), front contact and left-hand armature of relay 22 to ground. Also in positions 7 and 8 of the sequence switch 100, the trip magnet 23 is energized over a circuit from battery contact 123 (position 7 to 8), trip magnet 23 to ground, so that soon as the elevator shaft of the trunk selertor is again started into operation the proper set of brushes will be tripped. In position 8 of the sequence switch, the updrive magnet 21 is again energized over a circuit which extends from battery, through the up-drive magnet 21, contact 116 (position 8), front contact and lefthand armature of the relay 22 to ground. As soon as the elevator shaft is started in motion, the relay 22 is maintained energized over either of the following paths: from battery, left-hand winding of relay 22, the contact 117 (position 8),commutator 63, commutator brush 90 to ground, while the brushes are passing between terminals; or from battery through the right-hand wind in g of relay 22,'front contact and right armato the fifth thou- As soon as the relay 4 isreleased has ture thereof, test brush li and test terminals of busy trunks to ground. If the trunks are busy, there will be a. ground placed upon the contact (35 at the contact 251 (positions 2 and 18) of the trunk sequence switch 200. li'hen an idle trunk is encountered, both of these circuits are opened,

. one at the test brush (31+ and the other at the relay is deener gized. The deiiuergization of the relay '22 opens the circuit previously traced for the up-drive magnet :31 and stops the switch with the brushes in contact with an idle trunk. The release of the relay also establishes a circuit to drive the sequence switch 100 into position 5). This circuit ex tends from battery, through the motor magnet of sequence switch 100, contact lO-l (position le'l t armature and back contact of relay 22 to ground. Alter the idle trunk has been found the sequence switch 100 waits until all but the units impulses from the substation sender have been received and registered, or in other words. until the counting relay 1'? has been energized. When this occurs a circuit is established for the relay 2%, which may be traced from battery. through the armature and contact of stepping relay 9, contact 133 (position 9), relay 2% to ground. The relay EM closes a. circuit to drive the sequence switch 100 into position 10, which circuit extends from battery, through the motor magnet of sequence switch 100, contact L18 (position 9), right-hand. armature and colr tact of counting relay 16, right-hand armature and contact of counting relay ll, outer armature and contact of counting-5 relay 12, contact and. arn'iaturc of relay 24 to ground.

It will be observed that the sequenc switch 100 may in case of an abnormal delay on the part of the subscriber operating the sending dial move to position 10 before the units pulses have been registered. Since, in practice, the dialing and consequently impulse re istcrins operations take less time than the selection of a trunk, it is suilicient for all practical purposes to maintain the contacts i323 and llfl, which are included in the impulse storing: circuit closed during positions i to 9 oithe quence switch. However, if desired, it is obvious that these contacts may be main.- tained closed until position 13 or cven 'l i of the sequence switch, since in positions 1.9 to 13 the calling line registers may be operating to control the selection oi the'calling line Without in anyway interfering with the registering: operation of the called line tens and units registers.

In position '10 of the sequence switch 100 a circuit is established for the relay 220 sociated with the trunk and the stepping magnet 31 of the calling line hundreds register. This circuit extends from battery,

commutator (l3, and the relay 2:20, contact 202 (position 1) conductor 223, terminal 69, crush 67, conductor 70, con tact 119 (position 10), normal contact 71 of the register, contact 105 (position 10), magnet 31 to ground. The energization o the relay 220 in this circuit drives the sequence switch 200 into position 2, over a circuit which extends from battery, motor magnet of the sequence switch "200, contact 203 (position 1), front contact and righthand armatiju'e of relay 220 to ground. In position 2 of the sequence switch 200 a circuit is established for the up-drive' magnet 2:31 oi the calling line connector LC, which circuit extends from battery, through the up-drive magnet 22], contact 20% (position 2), front contact and righthand armature of the relay 220 to ground. As the elevator oi the line connector is thus driven upward, the brush passing over the commutator 2'25 intermittently shunts the stepping relay of the calling line hundreds register, by connecting ground to the circuit of the magnet 31. and relay 220 at the contact 202 (posit-ions i to 2.) by way of conductor 226. in response to the repeated. shuntings of the stepping magnet 31, the register brush 32 is moved back to normal. In the case assumed, alter five steps the contact 71 is opened, and the contact "4'2 is closed. The opening of: the contact 71 releases the relay 220 and the stepping magnet 31. The relay 220 in releasing: opens the circuit of up-' drive magnet 221 and closes a circuit to drive the sequence switch 200 into position 3. This circuit extends from battery, through the motor magnet of sequence switch 2-00, contact 203 (position 2), right armature and back contact of: the relay 220 to ground.

W hen contact '72 is operated a circuit is established to drive sequence switch 100 into position 11, which circuit extends from battery, through the motor magnet of sequence switch 100, conductor '73, contact 120 (position l0). contact 72 to ground. In position 3 of the sequence switch 200, a circuit established for trip magnet 222 of the calling, line connector, which circuit extends from ijiattery, through the trip magnet 2252, contact 201 (position 3), to ground, so that when the brush carriage is again set in motion the fifth set of brushes will be tripped, which set off, l'irushcs has access to the particular hunllred in which the calling line is located.

In position 3 m"- the sequence switch 200, and in position 1]. of the sequence switch 100, the relay 220 is placedin series with stepping magnet 25 of the calling line tens register. This circuit extends from battery, through the relay 220, contact 202 (position 3%). conductor 223, terminal 69, brush GT, conductor '70, contact 119 (position ll), normal contact 74; of the register, stepping right armature of relay 220 to ground. As

soon as the sequence switch 200 reaches position 4, a circuit for the UP-(l1'l"8 magnet 221 of the calling line connector is again established from battery, magnet 221, contact 204 (position 4), front contact and right armature of relay 220 to ground. Thestepping relay 25 is intermittently shunted, as the brush carriage moves upward, by a ground placed between the relay 220 and the stepping magnet 25, from brush 22?, coinmutator 228, contact 205 (position 1), conductor 229 to conductor 22? hen the register brush 45 is moved back to normal position, which in the case assumed will occur after five shuntings, the contact 74 is opened and the contact 75 closed. The opening of the contact 74 releases the stepping magnet 25 and the relay 220. The relay 220 when released opens the circuit previously traced tor magnet 221 and establishes a circuit to drive the sequence switch 200 into position 5, which circuit extends .from battery, through the motor magnet of sequence switch 200, contact 203 (position a), back contact and right-hand armature of therelay 220 to ground. The closing of the contact 75 establishes a circuit to drive the sequence switch 100 into position 12, which circuit extends from battery, through motor magnet of sequence switch 100, conductor 73, contact 120 (position 11). register con tact 75 to ground.

\Vith the sequence switch 200 in position 5 and sequence switch 100 in position 12. the. magnet 220 and the stepping magnet 20 of the calling line units register are placed in series over a circuit which extends from battery, through the relay 220, contact 202 (position conductor 223. terminal (35). brush 07, conductor 70, contact 11$) (position 12), register normal contact 70. stepping magnet 26 to ground. \Vhen relay 220 is operated acircuit is established to drive the sequence switch 200 into position (3. This circuit extends from battery. through motor magnet oi sequence switch 200, contact 203 (position 5), front contact 'and right-hand arn'iature of relay 220 to ground. As soon as the sequence switch 200 reaches position 6 a circuit is established for the lip-drive magnet 221 of the calling line con-.

nector. whi h circuit extends from battery. magnet 22]. contact 201 (position (3). front contact and right-hand armature of the relay 220 to ground. As the brush carrier movesupward. the stepping magnct26 is intermittently shunted by ground from brush 224, commutator 225, conductor 226,

to contact spring 202 in position 6. \Vhen the brush 47 of the calling line units register has been moved back to normal, which occurs after two shuntings, the contact 76 is opened and the contact 77 closed. The opening of contact 76 releases relay 220 and magnet 20. The release of relay 220 opens the circuit previously traced for the magnet 22] and drives the sequence switch 200 into position 7 ove a circuit which extends from battery. through motor magnet of sequence switch 200. contact 203 (position 6), back contact and right-hand armature of relay 220 to ground. The closing of the contact 7? drives the sequence switch 100 into position 13, over a circuit which may be traced from battery. motor magnet of sequence switch 100, conductor '73. contact 120 (position 1.2), register contact 77 to ground. Therefore. as a result of the operation traced so far. the calling line connector has been moved to connect the trunk to the calling line. In positions 1.3 .and 7 ot the sequence switches 100 and 200. respectively, a circuit is closed to drive the former sequence switch to position 14. which circuit is traceable from battery. motor magnet of sequence switch 100. sequence switch contact 118 (position 1?) brush (i0. terminal (58, and sequence switch contact 201 (position 7) to ground.

With the sequence switch 100 in position H and the sequence switch 200 in position 7. the relay 220 and the stepping magnet 18 of the hundreds called line register are included in a circuit extending from battery. relay 220. contact 202 (position 7), conductor 223. terminal (50, brush 07,0011- ductor 70. contact 121 (position 14). to register normal contact T8, stepping magnet 18 to ground. The eucrgization oi the relay 220 establishes a. circuit to drive the sequence switch 200 into position 8. which circuit extends from battery. through the motor magnet of the sequence switch 200. contact 203 (position 7). front contact and righthand armature o'l the relay 220 to ground. 'ith the sequence switch 200in position 8 and the relay 220 energized. a circuit is established for the updrive magnet 230 of the called line connector LC. which circuit extends from battery. through the up-drive magnet 2230. contact 204. (position 8), front contact and right armature of the relay 220 to ground. As the called line connector moves upward the magnet 18 of the register is intermittently shunted by a ground connected between the relay 220 and the magnet 18 by way of the brush 231. commutatm' 2232, contact 20:) (position 8). to conductor 229. .-\s it was assumed that the hundreds register was set on the third terminal after seven such shuntings. the register contact'TR is opened, releasing the relay 220 and the magnet 13. The release of relay 220 opens the previously traced circuit for the up drive magnet 230 and stops the called line connector and also closes at its back contact a circuit to drive the sequence-switch 200 into position 0, which circuit extends from hattcry, through motor magnet oi? the sequence switch 200, contact 203 (position 8), back contact and right-hand armature of the relay 220 to ground. At the time that the register contact 78 is opened, the register contact '79 is closed, and establishes a circuit to drive the sequence switch 100 into position 15, which. circuit extends from battery, through the motor magnet of sequence switch 100, conductor 72, contact 120 (position ll), register contact 79 to ground. Also in position 9 of the sequence switch 200 a circuit is established for the trip mag net from battery, magnet 233, contact 206 (position to ground so that when the elevator shaft of the called. line connector is again driven upward, the second set of brushes will be tripped.

\Vith the sequence switch 200 in position 9 and the sequence switch 100 in position 15, the relay 220 and stepping magnet 19 of the called line tens register are placed in series over the following circuit: battery, relay 220, contact 202 (position 9), conductor 223, terminal. 09, brush 07, conductor 70, contact 121 (position 15), register normal contact 80, stepping magnet 19 to ground. As soon as the relay 220 is en ergized, a circuit is established to drive the sequence switch 200 into position 10, which circuit extends from battery. through motor magnet of the sequence switch 200, contact 203 (position 9), front contact and right-hand armature of the relay 220 to ground. With the sequence switch 200 in position 10 a circuit is established for the up-drive magnet 230 of the called line connector, which circuit extends from battery, magnet 230, contact 204: (position 10), front Contact and right-hand armature of the relay 220 to ground. As the elevator shaft of the connector moves upward, the stepping magnet 19 is intermittently shunted by ground connected to the circuit between the relay and the magnet 19 from brush 234k, commutator 2355, contact 205 (position. 10), conductor In the case assumed, after eight shuntings of the magnet 19, the energizing circuit for the relay 220 and the magnet 19 is opened at register normal contact 80. The release of the relay 220 drives the sequence switch 200 into position 11 over a circuit which extends from battery, through the motor .magnet of sequence switch 200, contact 203 (position 10), back contact and armature of the relay 220 to ground. The release of the relay 220 also opens the previously traced energizing circuit for the updrive magnet 230 and stops the connector switch. When anemia the register returns to normahz'contact 81 is closed and establishes a circuit to drive the sequence switch 100 into, position 16, which. circuit extends from battery, through motor magnet of sequence switch 100, conductor 73, contact 122 (position 15), register contact 81, register contact 79 to ground.

With the sequence switch 100 in position 16 and the sequence switch 200 in position 11, the relay 220 and the stepping magnet 20 of the ialled line units register are placed in series in a circuit which extends from loattery, relay 220, contact 202 (position 11), conductor 223, terminal 69, brush 67, conductor 70, contact 121 (position 16), register normal contact 82, magnet 20 to ground.

As soon the relay 22-0 is energized in net 230, contact 204: (position. 12), front.

contact and armature of the relay 220 to ground. As the elevator shaft moves upward the stepping magnet 20 of the called line units register is intermittently shunted by a circuit which extends from conductor 223, conductor 229, contact 205 (position 12). After one shunting, in the case assumed, the circuit magnet 20, relay 220 is interruptedat the register normal contact 82. The release of the relay 220 at this time drives the sequence switch 200 out of position 12 over a circuit which extends from battery, through the motor magnet of sequence switch 200, contact 203 (position .12), the back contact of the relay 220 to ground. The release of the relay 220 at this time also opens the previously traced circuit from the rip-drive magnet 230 and stops the called line connector with the brushes 236, 237 and 238 in contact with the terminals 239, 240 and 241 of the called line. v

Before describing the testing operation. which takes place in positions 13 and 14 of the sequence switch 200, the ellect of the closing of the normal contact 83 of the called line units register will be consid cred. The closing of this contact establishes a circuit to drive the sequence switch 100 into position '17. which circuit extends from battery, through motor magnet of sequence switch 100, conductor 73, contact 122 (position 16), normal contact 83, normal contact 81, normal contact 79 to ground. As the registers are all restored to normal and the calling line and the called line connectors have been set on the terminals of the calling and called lines respectively, the apparatus, shown in Fig. 1, may

commutator 232, brush 231 to ground.

be released for use in connection with an circuit extends from battery to the motor magnet of sequence switch 100, contact 118 (position 17), conductor 87, contact 86, brush 85, to ground. In position 18 of sequence switch 100 a circuit is established for the downdrive magnet 88 of the trunk selector. This circuit extends from the battery to the downdrive magnet 88, contact 112 (position 18), to ground, when the trunk selector is then restored to normal] Provided there is no other line calling in the same group of lines to which the line finder is individual the relay 3 will be released owing to the fact that the group relay 2 is not energized, under which condition the sequence switch 100 is driven back to its normal position and the line finder may be again taken for use. This circuit for, driving the sequence switch 100 back to normal extends from battery, motor magnet of sequence switch 100, conductor 73, contact 122 in position 18, back contact and left-hand armature of relay 3, to ground. However, if there had been another line calling in the group when the sequence switch 100 reached position 18 such sequence switch will not be restored to normal as the relay 3 will be energized. This method of controlling the sequence switch 100 after it has reached its eighteenth position is employed for the pur pose of preventing a simultaneous starting of two line finders 1n the same group.

Returning now to the operation of the called line connector, as the sequence switch 200 passes position 13, if the called line is idle, there will be a battery potential on the test terminal 241 through the cut-oil relay of the called line, in which case the test relay 242 will be energized in series with the cut-oil relay of the called line over a circuit which extends from battery, through the cut-off relay of the called line, test terminal 241, test brush 238, contact 207 (position 13), back contact of relay 243, left-hand Winding of test relay 242, contact 208 (positions 13 and 14), right-hand winding of test relay 242, to ground.- The relay 242 when energized locks up at its left-hand armature and front contact and at its righthand armature establishes a circuit to drive sequence switch 200 into position 15, which circuit extends from battery, to the motor and calling lines versation.

magnet of sequence switch 200, contact 209 in position 14,- front contact and righthand armature of the relay 24-2, to ground. 'In position 15 of the sequence switch 200 a suitable source of ringing current, indi cated by the plus and minus sign adjacent the ringing cutoff relay 244,, is placed upon the line to signal the called subscriber. As i soon as the called subscriber answers, the ringing cut-oil relay 244 is encrgi over a circuit extending from ringing battery, relay 24 1, contact 209 (position 15), brush 237, terminal 240 through the suliscribers telephone set, to terminal 239, brush 236,

contact 210 (position 15), to ground. The

energization of the ringing cut-oil relay 244 when the called. subscriber answers drives the sequence switch 200 into position 16 over a circuit which extends from battery,

through the motor magnet. of sequence switch 200, contact 209 in position 15, armature and front contact of the ringing relay 244 to ground. The ringing circuit is opened in position 16 of the sequence switch and the circuit between the calling and called lines by way of contacts 209, 210, 211 and 212 is closed'in position 16. The called are then connected for con- If the called line is busy the relay fails to energize and when the sequence switch 200 reaches position 14 the relay 243 is energized over a circuit extending from battery, relay 243, contact 217 (position 14) back contact and left armature of relay 242, and connects a source of busy tone contact 213 through contact 214 (position 16) to the calling line. There. is no busy tone until the sequence switch 200 reaches position 16. The relay 243, however, in position 14 establishes a circuit for the downdrive magnet 245 of the called line connector which circuit extends from battery, to the downdrive magnet 2453, contact 214 (position 14), front contact and leftdiand armature of relay 243, to ground. When the called line connector reaches normal, the following circuit is established to drive the sequence switch 200 baclt to normal, from battery, through the motor magnet of sequence switch 200, contact 218 (position 14) normal contact 246', brush to ground.

As the sequence switch 200 passes position circuit is established to drive sequence switch 200 out of position 16, which circuit extends from battery, through the motormagnet ofisequence switch 5200, contact 209 (position .(16), back contact and armature of supervisory relay which happens to be denergized. In position 17 the calling line.

connector is restored as in the case of busy line, and in position 18 a circuit is estab-- lished for the downdrive magnet 245, of the called line connector by way of contact 215 (position 18), thus restoring all the apparatus to normal. I

What is claimed is: I 1. In a telephone exchange system, calling and called lines, a trunk line adapted to be utilized in establishing a connection between such calling and called lines, a line finder switch adapted to hunt for and seize a calling line, means controlled by the operation of a line finder to associate the trunk line with the calling line independent of such line finder, and means controlled through contacts of the line finder to associate the trunk line with v 1 the'oalled line.

2. In a telephone exchange system, calling and called lines, a trunk line adapted to be utilized in extending a connection between the calling and called lines, a registering andcontrolling circuit including a plurality of register controllers,- a line finder switch adapted to associate such registering and controlling circuit with the calling line, means for associating such registering and controlling circuit with the trunk, means controlled by the operation of a line finder in finding the calling line to set certain of such registers, means controlled over contacts of the line finder for. setting other of said registers, and means controlled by the registers for associating the trunk with both the calling and called lines.

3. In a telephone exchange system, calling and called lines, a trunk line, a line finder for hunting and seizing a calling line, a pair of automatic switches associated with such trunk line, means carried on the mov-. able part of such line finder and operated in the movement 'of the line finder to send directive impulses to one of such automatic I switches for the purpose of associating such trunlr with the calling line, and an impulse clrcult for controlling the setting of the other of such automatic switches controlled over contacts of such line finder for the purpose of associating such trunk with the called line.

4. In a telephone exchange system, lines I divided into groups, trunk lines individual to a group of lines extending to every other group, a pair of connector switches associated with each trunk line, a line finder switch adapted to hunt for and seize-a calling line, means controlled over the contacts of such line finder for directing one of such connector switches to the called line, and means controlled by the movement of the line finder to direct the other connector switch to the calling line.

5. In a telephone exchange system, lines divided into groups, a plurality of trunks extending from each group of lines to every other group, a line finder switch individual to a group of lines adapted to hunt for and seize a calling line in such group, means for automatically selecting an idle trunk leading from the group in which the calling line is located to the group in which the called line is located, means controlled by the operation of the line finder to connect.

the selected trunk to the callingline, and means for connectingsaid 'trunlc to the called line.

6. In a telephone exchange system, tele phone lines arranged in large groups and sub-groups, a plurality of trunk lines extending from each large group to each other large group, a plurality of line finders common to a large group adapted to hunt for and seize any calling line in such group, a trunk selector associated with "each line finder to select an idle one of such trunks, means controlled by the movement of the line finder to associate the selected trunk with the calling line, and means for associating the selected trunk with the called line controlled through contacts of such lin finder and such trunk selector.

7. In a telephone exchange system, telephone lines arranged in groups, registering controlling equipment for registering the designation of both the calling and called lines, a line finder for associating such equipment with the calling line, means for setting certain of such. registers to register the designation of the calling line controlled in the operation of such line finder, means for setting certain of such registers to register the designation of the called line, controlled from the calling line and through the line finder, and means under the control of such registers for establishing it connection between the calling and called ines.

8. In a telephone exchange system, telephone lines arranged in groups, trunks extending between such groups, a pair of conv a line finder switch for seizing a callingline, means controlled by the line finder'for setting one of such connector switches on the calling line, means controlled through the line finder for setting the other of such connector switches on the called line, and means for restoring the line finder to normalwhen the connector switches are set on the calling and called lines respectively.

9. In a telephone exchange system, calling and called lines, a trunk line arranged to establish a connection between such calling and called lines, a pair of switches associated with said trunk, an automatic switch arranged to seize a calling line, means controlled by the movement of the automatic switch for setting, one of the pair of switches on the calling line, and means controlled through the automatic switch for setting the other one of the pair of switches upon the called line. v

10. In a telephone exchange system, calling and called subscribers lines, a trunk line arranged to establish a connection between such calling and called subscribers lines, a pair of switches associated with said trunk, an automatic switch arranged to seize a calling subscribers line, means con trolled by the movement of the automatic switch for setting, one of said pair of switches on the calling line; and means controlled by the calling subscriber through the contacts .of the automatic switch for setting the other one of the pair of the switches upon the called line.

In witness whereof I hereunto vsubscribe my name this 29th day of December A. 1).,

JAMES 11. MCQUARRIE. 

